.modal {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: rgba(0, 0, 0, 0.3);
}

.wrap {
  width: 400px;
  height: 400px;
  background: #fff;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
}